Evaporator.



ASHTON HARVEY, 0F GREENWIGH, CONNECTICUT.

EVAPORATOR.

Specification of Iietterslatent.

Patented @ct. 29 rare.

Application filed October 22, 1915. Serial No. 57,224.

To all whom it may concern:

Be it known that I, AsH'roN HARVEY, a citizen of the .United States, residin at Greenwich, county ofFairfield, and tate of Connecticut, have invented a certam new and useful Evaporator, of which the following is a specification.

This invention is an evaporating apparatus for effecting the elimination of moisture from various substances, and it pertains, more particularly, to an improvement in machines of that kind embodying a series of chambers adapted to contain the material, or different kinds of material, to be treated by the circulation of heated air through said chambers and into contact with said material or materials.

. In the operation of. evaporating machines of this type, it is found desirable to subject similar materials present in two or more chambers to the action of air heated to dif ferent temperatures, in order that the results obtainable at such different temperatures on the same classes of material may be determined and compared for future use, etc. Furthermore, it is desirable during one operation of the machine to sub] ect a glven material in one compartment to air heated to a certain temperature, whereas other materials of different characters are required to be treated by air heated to different temperatures.

So far as I am aware no provision has been made in prior evaporators for heating to different temperatures the currents of air flowing into different chambers whereby the material present within said chambers are,

at one operation of the machine, subjected to treatment by heated air currents the temperatures of which vary to an appreciable degree.

In a practical apparatus of this character, provision is made as usual for initlally heatmg air as it enters the machine, which heated air is conducted by a feed duct or flue to independent chambers adapted to contain the material or materials to be treated.

The salient feature of my invention consists of heaters positioned in the path of the air currents as they flow from the feed duct into the separate chambers whereby said heaters impart additional heat to the air currents so as to raise the air to the different temperatures required or desired for the treatment of different batches of the same material or the various batches of different materials in the respective chambers.

Said heaters are usually supplied with steam from a header, the supply being under manual control or automatic control.

It is preferred to position the heaters in compartments provided at the upper ends of the material-containing chambers; to connect said heaters by separate feed pipes with the header; to provide said feed pipes with manually-operable valves; and to employ thermostatic valves in by-pass connections between the feed pipes and the header. But it will be understood that the various details may be modified or altered as found expedient by mechanics skilled in the art.

The drawing illustrates diagrammatically an evaporating apparatus embodying my invention.

A, B, G, Dtlesignate a series of chambers for containing the material or materials to be treated. As usual in this art, the chambers are provided with doors for obtaining access thereto, and are provided, also, with means of one form or another for supporting the material or materials in isolated batches and so that air is free to How into contact with such batches, one form of the material-supporting means being shown as a tray or shelf a E is a feed duct or fine common to all the chambers, and F is an exit flue connected with said chambers, said flues E F being shown at the top and bottom, respectively, of the chambers, but of course this arrangement can be modified as desired or found expedient.

The feed duct is connected with a chamber 9, within which are positioned preheaters G, such as steam coils or the like. A blower H forces air into the chamber 9 and into contact with the preheaters whereby the air is initially heated to a certain temperature preferably less than the temperatures at which the air is admitted to the separate chambers.

According to one practical form of my invention, each material chamber is provided at the top with partitions a, b, relatively spaced to form a compartment I, the latter being in communication with the chamber by an opening 2' and connected with the feed duct or flue by an opening i, said openings being at the opposite ends of said compartment I in order that the air from the flue or duct E may flow through the compartment T, thence into the material chamber.

The partitions b are shown as having baffles 6 extending into the flue or duct E for diverting some of the air into the compartments T.

Within the compartments T are the heaters or boosters J, thesame being shown as steam coils, although it is apparent that other forms of heaters may be employed. Said heaters are of such capacity as to impart to the preheated air flowing through the compartments additional heatfor the purpose of raising the temperature of the air to a desired degree or degrees. Thus, the heater or booster J for chamber. A will, under some conditions, operate to heat the air to a temperature of 180 Fahrenhiet, whereas the heaters or boosters for the other chambers will increase the air to 200, 212

and 220 Fahrenheit for the remaining chambers B C and D, respectively, although it is apparent that the described variation in temperatures is merely illustrative and ing provided with a manually operable valve L, whereby the steam supply to the heaters or boosters may be turned on or shut off as required.

In addition to the manua1ly-operable valve L means are provided for effecting the automatic regulation of the steam supply to the heaters or boosters so that, after closing valves L when the machine is in operation, the temperature within each chamber is controllable without attention on the part of the workman to the end that the steam supply may be shut ofl' in the event of the heat exceeding a predetermined temperature within the chamber or should the heat fall below the predetermined degree the steam will be supplied automatically to the heater, for the purpose of heatin the air so as to restore the temperature esired or required to be maintained within the chamber. As. shown, a by-pass 0 is connected to each branch pipe la and to the header K, each by-pass havinga valve P operable by suitable means under the control of a thermoasaeae stat Q, but normally the valve P is closed so that steam cannot pass through the byto the chambers are closed, steam is supplied to the preheaters G, and the blower started for blowing air in the volume required into the machine. The air israised to a desired temperature by flowing into contact with the preheaters G, thence the air flows through duct or flue E, compartments T, the treating chambers and the exit flue F to the stack or uptake, the heated air flowinginto contact with the material or materials supported upon the trays or shelves for the purpose of absorbing moisture from said material and eflectmg the drying thereof.

With the valves L F closed, no steam is admitted'to the heaters or boosters J, hence the airflowing through the chambers A to D inclusive will be at the temperature to which the air is initially heated by the preheaters Gr, minus the small percentagelost by radiation; but as already explained, it is frequently necessary tosubject difl'erent batches of the same material within two or more of the chambers A B C or D to heated air the temperatures of which vary, say from 180 Fahrenheit to 220 Fahrenheit, or it may become necessary to'treat in the separate chambers batches of differ ent materials with air heated to diflerent temperatures. The apparatus embodying the heaters positioned at the air inlets to the separate chambers, said heaters being under manual or automatic control, provides means whereby the temperature of the air flowing into the respective chambers is controllable to meet the requirements of the treatment to be accorded to the batches of material or materials. It is apparent that the heater J associated with chamber A may be brought into service for heating the air to a temperature of 180 Fahrenheit as it flows from flue E to chamber A. Further, the heaters J which cooperate with the other chambers B, C, D, are controllable by the valves L for heating the air to the temperatures necessary for treatment of the material or materials present in said chambers; thus the air flowing through chamber B may require to be heated to 200 Fahrenheit; in the case of chamber C, the air may be reheated to a temperature of 212 Fahrenheit, or in the case of chamber D the air is to be raised to a temperature of 220 Fahrenheit. Of course, the foregoing examples are illustrative only of the temperatures required.

When the machine is in operation, the

aaeaeaa valves L may or may not be closed to shut ofi the steam supply to the heaters or boosters, but the temperature within the heaters will be maintained as required by the automatic operation of the thermostatically controlled valves P in the by-pass connections 0' between the header with the individual heaters or boosters.

Having thus fully described the invention, what I claim as new, and desire to secure by Letters Patent is:

1. An evaporating apparatus embod ing a plurality of material-containing cham ers,

means for feeding heated air thereto, a plurality of separate heaters one positioned substantially at the air inlet to each of said chambers, and means whereby said heaters are controllable at will for heating to different appreciabletemperatures the currents of air flowing into said separate chambers.

2. An evaporating apparatus embodying a plurality of material-containing chambers, means for feeding air to said chambers, means for preheating the air, a plurality of heaters independent of each other and one positioned substantially at the air inlet to each of said chambers, and means for controlling the flow of a heating medium to the separate heaters whereby the currents of preheated air flowing to said chambers may be reheated so that said separate air currents are heated to difl'erent temperatures as they flow into the independent chambers.

partments are adapted to 'be reheated or boosted to appreciably difierent temperatures as they enter said compartments.

4:. An evaporating apparatus embodying a plurality'of material-containing chambers, a feed duct or'flue for supplying preheated air to said chambers, a pluralit of heaters independent of each other and positioned substantially at the air inlets to said chambers, a header having separate connections with said heaters, and means for controlling the flow of a heating medium from said header to the separate heaters whereby said heaters may be individually brought intoservice for reheating the air so that the air currents will be raised to appreciably different temperatures as such currents flow into the separate chambers.

5. An evaporating apparatus embod ing a plurality of materlal-containing cham ers, means for feeding air thereto, a plurality of heaters independent of each other and positioned substantially at the air inlets to said chambers, means for feeding a heating medium to said heaters, and means controllable at will for regulating the flow of the heating medium to the separate heaters whereby said heaters are operable individually for reheating to appreciably difierent temperatures'the air flowing into the separate chambers.

6. An evaporatingapparatus embodying a plurality of material-containing chambers, means for feeding air thereto, a plurality of heaters independent of each other and positioned substantially at the air inlets to said chambers, means for feedin a heating medium to said heaters, and t ermostaticallycontrolled means the operation of which is dependent upon the temperatures prevailing in said chambers for regulating the flow of. a heating medium to said individual heaters.

In testimony whereof I have signed my name to this specification.

ASHTON HARVEY. 

